Particulate clay is by far the most common animal litter utilized by pet owners in litter boxes that are kept indoors. However, the development of odors in the litter boxes as they are utilized by a pet represents a serious problem.
Heretofore numerous attempts have been made to improve the deodorizing properties of animal litter. Illustrative of such attempts are U.S. Pat. Nos. 2,895,873 and 3,029,783 in which is disclosed the in-situ formation of aluminum sulfate by the reaction of sulfuric acid with the alumino silicates present in the clay together with the use of an onium compound as a germicide. U.S. Pat. No. 4,494,482 discloses solid absorbent materials having adsorbed thereon a halogenated aromatic hydrocarbon bacteriostat. U.S. Pat. No. 4,341,180 describes the use of bactericides such as cetylperidium chloride, cetalkonium chloride, and the like in pelletized rejects of a secondary fiber plant. The use of a disinfectant, germicide, or fungicide in poultry or animal bedding is also mentioned in U.S. Pat. No. 2,708,418.
Other attempts to resolve the odor problem include the controlled release of a masking fragrance when a clay litter material is wet by voided body fluids as described in U.S. Pat. Nos. 3,675,625, 3,921,581, 4,009,684 and 4,020,156 as well as the use of specific deodorizing materials such as chlorophyll, alkali metal dihydrogen phosphates, potassium acid phthalate, or combinations thereof, as described in U.S. Pat. No. 3,735,734. The use of ferrous sulfate heptahydrate for deodorizing animal litter is described in U.S. Pat. No. 3,776,188. An animal litter said to absorb and neutralize odors and prepared from a mixture of alfalfa, bentonite and a binder therefor is described in U.S. Pat. No. 3,789,787. A deodorant for animal litter consisting of magnesium carbonate and borax is described in U.S. Pat. No. 3,352,792. The use of Vitamin E in animal litter for odor-abatement is described in U.S. Pat. No. 4,007,708.
Materials and compositions other than clays but said to have odor abating properties have also been proposed as animal litter. Acid buffered cellulosic materials are described in U.S. Pat. No. 3,059,615. Dehydrated alfalfa is described in U.S. Pat. No. 3,286,691. A mixture of alfalfa with perlite or vermiculite is described in U.S. Pat. No. 3,425,397. Camphane derivatives in combination with organic or inorganic animal litters are described in U.S. Pat. No. 3,636,927.
Foamed plastics combined with deodorizers are described in U.S. Pat. No. 3,765,371. Cherry pit extract in combination with animal litter is described in U.S. Pat. No. 3,816,577. Animal litter derived from popcorn, alone or admixed with clay or alfalfa is described in U.S. Pat. No. 3,916,831. The use of peanut hulls containing sodium bicarbonate as animal litter is described in U.S. Pat. No. 3,983,842. The use of absorbent fly ash, bottom ash, boiler slag, with or without Fuller's earth and with or without an in-situ polymerized monomer having an acidic functional group is described in U.S. Pat. Nos. 4,129,094 and 4,506,628.
The foregoing diverse approaches to odor control in animal litter amply demonstrate that a practical solution to this problem has been elusive. Some of the heretofore proposed approaches have not proved to be commercially practical from a functional standpoint, from a toxicity standpoint, and/or from a cost standpoint.
It has now been found, however, that effective odor abatement can be achieved in animal litter derived from naturally-occurring as well as synthetic materials by means of an odor-abatement agent that is safe to the pet, relatively non-toxic, and relatively inexpensive.